Use HTTP methods in JdkClientHttpRequest when possible

Prior to this commit, we would use the
`java.net.http.HttpRequest.Builder#method(String, BodyPublisher)` to
create HTTP requests for the JDK HttpClient. This method requires a
non-null body publisher; providing an empty publisher writes a
"Content-Length: 0" header to all requests.

As of Java 19, this behavior changes for `HttpRequest.Builder#GET` and
similar methods, where the body publisher is considered as null and no
"Content-Length" header is written.

This commit aligns with this behavior and favors dedicated HTTP methods
whenever available.`

Closes gh-34971

spring-web/src/main/java/org/springframework/http/client/JdkClientHttpRequest.java

@@ -149,7 +149,16 @@ class JdkClientHttpRequest extends AbstractStreamingClientHttpRequest {
 			}
 		});
 
-		builder.method(this.method.name(), bodyPublisher(headers, body));
+		switch (this.method.name()) {
+			case "GET" :
+				builder.GET();
+				break;
+			case "DELETE" :
+				builder.DELETE();
+				break;
+			default :
+				builder.method(this.method.name(), bodyPublisher(headers, body));
+		}
 		return builder.build();
 	}